The application of thin coatings of coating materials, i.e. less than about 10 microns, has become an increasingly important step in the manufacture of various products including, for example: fiat panel displays, such as those used in lap top computers, high definition television and cathode ray tubes; optical devices, such as, lenses, color filters and mirrors; hybrid circuit boards; silicon wafers and germanium wafers.
One particularly useful apparatus for applying thin coatings to objects is described in U.S. Pat. No. 4,370,356, issued Jan. 25, 1983. The patent discloses an apparatus for coating the surface of an object with a coating material. The apparatus comprises a vacuum chuck assembly which is pivotably mounted in the apparatus between an upward position, wherein the object can be placed onto the vacuum chuck assembly such that the surface of the object faces generally upward, and a downward position, wherein the surface of the object faces downward in a generally horizontal plane and the object is held in place by vacuum. The apparatus further comprises an applicator, i.e., a coating material applicator, which is movably positioned beneath the vacuum chuck assembly in order to traverse the surface of the object in a generally parallel direction to the surface of the object. When the coating material applicator is traversed beneath the surface of the object, coating material is transferred from the applicator to the surface of the object. The patent also discloses a means for introducing the coating material through the applicator onto the surface of the object, e.g., a pump. In addition, the patent discloses that the vacuum chuck assembly is movably positioned within the frame of the apparatus to move from a loading position, wherein the object can be loaded onto the vacuum chuck assembly, to a coating position, wherein the coating is conducted, and finally to a heating or drying position, wherein volatile components in the coating material can be removed.